These are the rules for F/TR . . .

First: "TR", standing for "Target Rifle", is a subcategory of F-Class competition,
limited to .223- and .308-caliber rifles. These rifles must be fired off a bi-pod only.

F-T/R class is firing a .308 (or .223) rifle at ranges from 300 yards to 1200+ yards. These rifles are only allowed to fired off a bi-pod only. NO front rifle rest allowed. The target used is the long-range F-Class target. The “X” ring on the target is 1/2 MOA (or 5″ circle at 1000 yards). The only permitted support for F-T/R rifles are a sling or a bipod (or both, although it is rare for an F-T/R shooter to use a sling). The weight limit for the class is 8.25 Kg (or 18.15 lbs). F-Class rifles may be shot using iron sights, but 99.9% of F-T/R shooters use scopes.

Also, you may want to check out this website:

http://www.nrahq.org/compete/RuleBooks/HPR/hpr-w22.pdf